Flying cut-off



March 21, 1967 J. 5. WALSH FLYING CUT-OFF 5 Sheets$heet 1 Filed Jan. 8. 1964 INVENTOR.

JOSEPH S. WALSH way I Q "m ATTORNS March 21, E967 J. 5. WALSH FLYING CUT-OFF 5 Sheets-Sheet 2 Filed Jan. 8. 1964 INVENTOK JOSEPH .3.

WALSH BY Q a in ATTORNEVQ J. S. WALSH FLYING CUT-OFF March 21 1%6'7 5 Sheets-Sheet 4 Filed Jan. 8. 1964 VALVE 242 United States Patent 3,3ti9,952 FLYING CUT-GFF Joseph S. Walsh, Fairview Park, ()hio, assignor to The goder Company, Cleveland, Ghio, a corporation of bio Filed Jan. 8, 1964, Ser. No. 336,417 24 Claims. (Cl. 83-37) This invention relates as indicated to a flying cut-off and more particularly to a high speed fast cycling cut-off for tube mills and the like.

In continuous strip processing lines, such as cold roll forming operations, the speed at which the line or mill may operate often depends upon the speed and efiiciency of the work cut-off. Perhaps the most common flying cut-off employed today in such operations is a shear type cut-off press. If the shapes to be cut are sufficiently stiff, the work itself may be employed to push the die table which includes the cut-off dies forward at the speed of the work to obtain the flying shear. The more complex type is that which has a powered die table, such being necessary where shapes to be cut lack sufiicient stiffness to push the cut-ofl die forward without buckling.

In any event, both types of shear cut-offs require very heavy framing accurately machined to ensure proper alignment of the moving parts, a crankshaft specially treated and also accurately machined, special crankshaft bearings, and a clutch and heavy drive motor for operation of the crankshaft. The more complex type of cutoff additionally requires a drive for the die table to accelerate such to the speed of the work, and then stop the die table and return it to its original position. Reference may be had to the copending application of Charles J. Bognar, Ser. No. 39,250, filed June 28, 1960, now Patent No. 3,169,429, granted Feb. 16, 1965, entitled, Flying Tool Mechanism for an exemplary disclosure of a flying cut-off having a powered die table. Thus it will be seen that conventional shear type cut-offs, while satisfactory in many lines, are still heavy, complex, expensive, and occupy a substantial amount of space. Moreover, such machines are limited both in the maximum number of cuts per minute as well as the maximum stock speed that may be obtained.

It is accordingly a principal object of the present invention to provide a cut-off which can make a large number of cuts per minute and also accommodate an extremely high stock speed.

A further principal object is the provision of a cut-off capable of such rapid cycling which is yet of an extremely simple and inexpensive construction.

Another object is the provision of such a cut-off which does not require expensive drive motors, shafts, clutches, and the like.

A further object is the provision of a cut-olf for tubing and the like wherein the cycle of operation is such that the blade does not require to move through one complete reciprocatory stroke, but need merely shift position.

Yet another object is the provision of a lightweight tube cut-off utilizing extremely high cutting velocities and the blade of which may susbtantially explosively be driven through the Work.

Still another object is the provision of a tube cut-off utilizing a unique blade support and drive means therefor.

A yet further object is the provision of a cut-oif blade and support therefor in which the blade is mounted for slight resilient movement in the direction of the travelling work.

A yet further object is the provision of a double edge blade for a tube cut-off which will obtain a faster yet improved severing of the tube.

Other objects and advantages of the present invention 3,309,952 Patented Mar. 21, 1967 will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed draw ings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a side elevation partially broken away and in section of a tube cut-off in accordance with the present invention;

FIG. 2 is a top plan view also partially broken away and in section of such tube cut-01f;

FIG. 3 is an enlarged vertical section taken substantially on the line 33 of FIG. 2 showing in side elevation the tube enclosing dies which include the tube grip ping collets and carriage therefor;

FIG. 4 is a fragmentary top plan view of such collets and the carriage therefor partially broken away and in section as seen from the top of FIG. 3;

FIG. 5 is a fragmentary end elevation as seen from the right in FIG. 4;

FIG. 6 is a fragmentary vertical section on a somewhat reduced scale taken from the center of the collet and carriage corresponding to FIG. 3;

FIG. 7 is a fragmentary vertical section taken substantially on the line 77 of FIG. 6;

FIG. 8 is an enlarged horizontal section illustrating the mounting of the blade in its travelling frame as taken substantially on the line 8-8 of FIG. 9;

FIG. 9 is a fragmentary front elevation illustrating the blade mounted in its frame and the profile thereof;

FIGS. 10 through 17 are schematic flow diagrams illustrating the operation of the cut-off through one complete cycle or two successive cutting operations; and

FIG. 18 is a schematic circuit diagram further showing the cycle of operation of the cut-off.

Referring now to the annexed drawings and more particularly to FIGS. 1 and 2, the illustrated cut-off may be mounted on a base 1 which may comprise simply an I-beam having top and bottom flanges 2 and 3, the former serving as a table top for the support of the cut-off. Such base beam extends transversely of the direction of the work travel which may be in the direction of the arrow 4 in FIG. 2 and normal to the plane of FIG. 1. It will be understood that the base 1 may be mounted on a stand for support at the proper height and such stand may be mounted for movement into and out of the mill line. Although the illustrated cut-off is particularly adapted for use in a tube line, it will be appreciated that other rolled or extruded shapes may be severed with the present invention. Moreover, the cut-off of the present invention may, of course, be utilized to sever tubes or shapes manually fed thereto rather than in a high speed automatic line.

Mounted on the top 2 of the base 1 are three upstanding support stanchions 6, 7 and 8, which are substantially similar. Such blocks are mounted on support pads 9, 10 and 11 which are fastened through shims 12 to the top flange 2. Such shims may be welded to the top 2 and properly horizontally aligned so that the stanchions also will be properly positioned. Such fasteners may be the illustrated nut and bolt assemblies 13, four for each stanchion passing through the support pads, shims and the top flange 2. In this manner, the stanchions are removably yet firmly secured to the top of the base.

The stanchions 6 and 7 are provided with aligned countersunk central apertures 15 and 16 and securely fitted in the countersunk portions thereof and extending therebetween is a heavy duty air cylinder 17. Mounted in the apertures and :16 are flanged retaining rings 18 and 19 secured by fasteners 20 through the flanges thereof to the exterior of the stanchions 6 and 7. Such rings have central apertures therethrough slidably supporting therein piston rod 21 which extends completely through the cylinder 17. Such rings 18 and 19 may be provided with internal shoulders accommodating bushings 22 and 23 as well as internal grooves accommodating seal rings 24 and 25. A piston 27 is mounted on the rod 21 for reciprocation within the cylinder 17. A piston-cylinder assembly is thus formed wherein both sides of the piston 27 within the cylinder 17 have equal areas exposed to the pressures within the cylinder so that equal forces will be obtained to move the piston and thus the rod 21 in either direction of reciprocation.

The stanchions 6 and 7 are provided with L-shaped passages indicated at 30 and 31 which communicate with the ends of the cylinder 17 and with shuttle valve housings 32 and 33, respectively, such being secured to the inside opposed faces of the stanchions 6 and 7. Each shuttle valve housing includes a central bore shown at 34 and 35 in FIG. 2 and shuttle valve members 36 and 37 are mounted in such bores for reciprocation. The ends of the bores 34 and 35 of each shuttle valve are closed by flanged rings 39 and 40 having tapped ports 41 and 42 therein for connection of high pressure pneumatic conduit thereto. Thus when air pressure is applied to the port 42, the shuttle valve member 37 will be shifted against the ring 39 blocking the port 41. Conversely, when the shuttle member 36 is shifted against the ring 40 by pressure being applied through the port 41, the port 42 will be blocked. In either position of the shuttle, the ports 43 and 44 of the valves will be opened communicating with the passages 30 and 31 leading to the opposite ends of the cylinder 17.

A block 47 is centrally mounted on the cylinder 17 having an aperture therein through which the cylinder extends. Flaring exhaust ports 48 and 49 in the block 47 communicate with apertures in the wall of the cylinder to provide exhaust ports for the piston-cylinder assembly. Seal rings 50 and 51 mounted in internal grooves in the block 47 surround the cylinder 17.

Extending between the stanchions 7 and 8 are two vertically spaced guide rods 55 and 56, with the former or upper guide rod 55 being of slightly larger diameter. Such guide rods may be threaded into the stanchion block 7 as indicated at 57 and include reduced diameter portions 58 and 59, respectively, which extend through the stanchion 8 and which are threaded and have secured thereon nuts 60 and 61. The rods 55 and 56, which may be highly polished, are thus firmly held between the stanchions 7 and 8 in parallelism. The rod 21 extending through the ring 19 is connected at to window frame unit 66 which comprises U-shaped members 67 and 68, the opposed legs of which are joined by retainer assemblies 69 and 70 for double edge cutting blade B.

Secured as by welding to the top of the frame 66 are rings 72 and 73 provided with bushings 74 and 75 which surround the upper guide rod 55. Similarly, somewhat smaller and slightly closer spaced rings 76 and 77 are secured as by welding to the bottom of the frame 66 housing bushings 78 and 79 enclosing the lower or somewhat smaller guide rod 56. The frame 66 is in this manner firmly supported between the rods 55 and 56 and yet freely slidable back and forth therealong.

Laterally projecting pins 81 and 82 extend a slight distance from the frame 66 and are adapted to engage latches 83 and 84 pivoted at 85 and 86 internally of the stanchions 7 and 8, respectively. Each latch is provided with an inclined leading edge 87 which terminates in the latching step 88 behind which the pins 81 and 82 are adapted to engage. Actuating rods 90 and 91 are pivotally con- 4.- nected at 92 and 93 to the latches S3 and 84, respectively. Such rods extend through apertures in the top 2 of the base 1 and are extended and retracted by actuators such as solenoids 94 and 95. Such solenoids may be secured to the web of the I-beam base *1 by fasteners 96 through suitable mounting brackets.

It can now be seen that the frame 66 is mounted for reciprocation between the guide rods 55 and 56 by actuation of the piston-cylinder assembly 17, 27, and that the frame may be held at either end of its horizontal stroke by the latches 83 and 84. The connection 65 between the rod 21 and the frame 66 may serve as a bumper limiting movement of the frame to the left as seen in FIG. 1 and a similar bumper 98 may be provided at the opposite end of the frame.

Since the work, illustrated as a relatively small diameter tube T in FIG. 1, will be moving quite rapidly in the direction of the arrow 4 in FIG. 2, the blade B is mounted for slight lateral movement within the frame 66 by means of the retainer assemblies 69 and 70 illustrated in more detail in FIGS. 8 and 9. Each retainer assembly includes front and back plates 100 and 101 which bridge the legs of the U-shaped frames 67 and 68 and are secured thereto and to each other by suitable fasteners such as the recessed screws 102 and 103. The plate 100 is provided with a pair of horizontally aligned apertures 104 and 105 in which are situated bushings 106 and 107 accommodating thrust pins 108 and 109 for movement therethrough. Similar apertures 110 and 111 are provided in the rear plate 101 accommodating bushings 112 and 113, such being aligned with the bushings in the plate 100 and accommodating the thrust pins 108 and 109. The back plate 101 is recessed as indicated at 115 to permit relatively short movement of blade carrier 116 which includes a back U-shaped member 117 which is welded as indicated at 118 to the thrust pins 108 and 109 and a fillet plate 120 extending between the legs of the U-shaped member 117 and confining the blade B in the blade carrier. Thus the blade B is securely confined between the members 117 and 120 with the former being welded to the thrust pins 108 and 109 so that the blade carrier includes such thrust pins which are mounted for movement in the aligned bushings 106, 107, 112 and 113. A back-up plate 122 is welded to the back plate 101 and serves as a seat for the return springs 123 and 124 which are mounted in circular apertures 125 and 126 in the back bridging plate I101.

The blade B, secured in the carriage 116, is normally held with the carriage seated against the front plate 100 is illustrated in FIG. 8, but it will be appreciated that the carriage may move a distance equal to the depth of the recess 115 in the back plate 101 compressing the return springs 123 and 124. In the illustrated embodiment, this distance may be on the order .of of an inch. The blade will be mounted in similar carriages both top and bottom in the retainer assemblies 69 and 70 and in this manner secured to the frame 66 and yet having lateral play or movement permitting the blade to travel with the Work for a short distance as the blade moves from left to right and back again through the work as the result of the reciprocation of the carriage 66.

The blade B, shown in profile in FIG. 9, is especially adapted for severing continuous lengths of tubing and includes top and bottom rectangular portions 130 and 131 which are mounted in the top and bottom carriages of the frame 66. Between such portions extends the blade proper which includes oppositely directed projecting tube severing portions 132 and 133. The oppositely directed tube severing portions of the blade, which will shear a relatively thin section from the workpiece to make the cut, are identical in form and accordingly only that edge on the right shown in FIG. 9 will be described in detail. It is noted that the blade is completely symmetrical about the center thereof, both about the vertical center line as well as the horizontal center line. Reading from the top to the bottom on the right hand edge, as seen in FIG. 9, such blade includes concave, convex, concave curved edge portions 134, 135 and 136 which are tangent to each other with the concave curve 136 terminating in a blunt convexly curved pointed portion 137. The lower side of the right hand blade edge includes curves 138, 139 and 140 which are symmetrically disposed with respect to the respective curves 136, 135 and 134. The blade edge is thus composed of two reverse curves which are symmetrical about the horizontal center of the blade and each of which includes three distinct tangential curved segments. The centers for the curves 134, 135, and 139, 140 may be vertically aligned while the centers for the terminal curves 136 and 138 may also be vertically aligned with each other and preferably with the tip edge 137 of the blade. The chordal dimension of the projecting portions of the blade indicated at 140, which is the distance between the tangent points between the curves 134 and 135 and 139 and 140 may be slightly larger than the diameter of the tube to be severed. For example, for a 1 inch tube diameter, such dimension 140 may be approximately of an inch. For example, for a 1 inch tube, the curve 134 may be struck on a inch radius while the curve 135 is also struck on a inch radius. The curve 136 may be struck on a /2 inch radius and the curved tip 137 may be struck on a A inch radius.

The thickness of the blade should preferably be no greater than the wall thickness of the work to be severed. It is, of course, desirable to utilize as thin a blade as possible.

For example, assuming that the blade is moving to the left in FIG. 9, the projecting curved pointed portion 137 will initially enter the tube T and the curved portions 136 and 138 on either side and adjacent the tip 137 will maintain the edge of the blade at the point of actual severing substantially tangent to the mean diameter of the tube T. Thus as the blade moves relative to the tube to the phantom line condition indicated at 141, that portion of the blade severing the tube will still be substantially tangent to the mean diameter of the tube. By utilizing the reverse curve portions 135 and 139, improved metal removal has been obtained on the far or second side of the tube as the blade moves therethrough. As the point 137 moves through the back side of the tube, it will start to shear two thin strips from the tube on opposite sides of the point and the outer reverse curve portions 135 and 139 will continue to sever the tube around the front periphery thereof. Such severing portions will then meet to shear two thin strips from the tube on opposite sides of the point thus completing the severing operation.

In will, of course, be appreciated that other blade profiles may be employed with the present invention for severing different shapes. Moreover, for different size tubes, other shapes may be employed utilizing the same reverse curve features of the illustrated blade profile.

Referring now to FIGS. 3 through 7, it has been demonstrated how the blade B is mounted for short distance movement with the tube T as the blade passes therethrough. To facilitate the severing operation, entry and exit dies 150 and 151 are provided on opposite sides of the blade which will grip the travelling tube momentarily as the tube moves through the cut-off firmly holding the same for the severing operation. Such dies, which include tube gripping collets, illustrated more clearly in FIGS. 6 and 7, are secured together and mounted for movement on carriage 152 between brackets 153 and 154 which are secured by suitable fasteners 155 to the top 2 of the base 1 and additional fasteners 156 may be employed securing the base of such brackets to the web of the base beam 1. Each bracket is provided with a vertically extending slot as indicated at 158 and 159, such slot flaring outwardly and being provided with a rounded bottom surface as indicated in FIG. 5 at 160.

Mounted in the legs of the brackets formed by the center slots which accommodate the tube therethrough are inwardly projecting guide rods 161 and 162 mounted on the bracket 154 and rods 163 and 164 mounted on the bracket 153. Such guide rods may be secured in place by set screws or the like 165 extending through the tops of the brackets on eitherside of the tube accommodating slots.

The carriage 152 includes two castings 166 and 167 secured to the bottom of die blocks 168 and 169, respectively, by fasteners 170 and joined together by fasteners 171 passing through the opposed laterally directed flanges 172 and 173 with a shim 174 interposed therebetween. The castings 166 and 167 each include depending web portions which join the flanges through which the fasteners 17% pass into the die blocks 168 and 169 and the vertically directed laterally extending flanges 172 and 173 by which such castings are joined. The castings thus join the die blocks 1'68 and 169 beneath the lower guide rod 56 permitting adequate clearance for movement of the collars or rings 76 therebetween. As seen more clearly in FIG. 7, each of the castings is provided with a central channel 176 accommodating the tips 177 and 178 of locking forks 179 and 139 which are mounted in vertical slots 131 and 182 in the die blocks 168 and 169. (See FIGS. 5 and 7.)

The die blocks 16S and 169 includes central chambers shown at 184 and 185 in each of which are situated opposed collet members 186 and 187. Such opposed collet members are identical in form and include central semi-circular recesses 139 which, when the collet members are moved together, will enclose and grip the tubular workpiece passing therethrough. Such collet members include reduced diameter extensions 190 which project toward each other inwardly toward the path of the cutting blade B closely confining and gripping the tubular workpiece adjacent the point of severing. The backs of the collet members are provided with vertical grooves having inclined wedge surfaces corresponding to the inclined wedge surfaces of the legs of the collet actuating forks 179 and 139. I The collet members are retained at the bottom by the central portion 192 of the die blocks between the slots 181 and 132 for the tips of the collet forks, and at the top are confined by plate 193 which includes vertical slots 194 and 195 accommodating the legs of the forks for movement therethrough.

Collet actuating piston-cylinder assemblies 197 and 198 are mounted on plates 199 and 2%, respectively, each of which is supported vertically spaced from the plates 193 on top of the die blocks by legs 2131 and 2132. Elongated fasteners 2114- and 295 extend through the plates 199 and 201), the legs 291 and 292 supporting the same, and the plates 193 to extend into the respective die blocks securing the parts together. The piston rods 207 and 298 of the piston-cylinder assemblies extend through the plates upon which the piston-cylinder assemblies are mounted and are secured to the bight portions of the collet actuating forks. Thus extension and retraction of the piston-cylinder assemblies 197 and 193 will vertically move the collet actuating forks thus to cause the collet members to move to and from a tubular workpiece gripping position.

To guide the tubular workpiece to and from the cylin drical recess in the collect members formed by the semicircular openings 189, each die block is provided with an insert indicated at 210 having a flaring inner guide surface 211. In this manner, a tubular workpiece entermg from the right as seen in FIGS. 3, 4 and 6 will pass through the slot 158 in the bracket 153 and be guided by the flaring surface 211 of the insert 210 into the recess formed by the semicircular surfaces 189 of the collets 186 and 187 of the assembly 150.

With the blade B retracted and latched in either position, the tubular workpiece will pass through the other collet assembly, out through the insert and finally through the slot 159 in the bracket 154. When the piston-cylinder assemblies 197 and 198 are energized to extend the piston rods 207 and 208 thereof, the forks 179 and 180 will be moved downwardly forcing by the wedge action of the fork fingers the collect members 186 and 187 toward each other thus gripping the tubular product in the passage therethrough. The workpiece will then be firmly gripped at closel spaced portions on either side of the path of the blade B.

The fingers of the collect actuating forks have inside surfaces with approximately a taper and a three surface seat will be provided for such collet members in the tube gripping position. As the fork 179, as seen in FIG. 7, is moved downwardly, a firm three surface seating will be obtained at the three surfaces 212, 213, on the inside of the fork, and the bottom surface 214 at the top of the center portion 192 of the die block 168. It is noted that the vertical split between the collet members 186 and 187 is normal to the direction of blade travel which is in a horizontal plane or moving from right to left as seen in FIG. 5, and the points of the blade will then bite into the tube at a solid part of the collet members and not along any split line. Thus the point of impact between the point of the blade in the tube is 90 offset from the split line of the collet members.

The piston-cylinder assemblies 197 and 198 may preferably be pneumatically actuated and will serve to grip the tubular workpiece for only a very short period of time while the actual severing thereof takes place. When the tubular workpiece is thus gripped, the carriage 152 will be caused to move with the workpiece and will slide along the guide rods 161 through 164 which are mounted in the brackets 153 and 154. For this purpose, the guide rods extend through bushings 216 mounted in apertures 217 in the die blocks. (See FIG. 7.) When the tubular workpiece is gripped, the carriage 152 supporting the work gripping collets will then move to the left as seen in FIG. 3, for example, at approximately the same time that the blade B is entering the workpiece, and thus the carriage 152 and the blade mounted in its yieldable blade retainers seen in FIGS. 8 and 9 will both move a relatively short distance with the workpiece as the blade passes therethrough. When the blade has completed the severing operation, the piston-cylinder assemblies 197 and 198 will be retracted releasing the tubular workpiece for continued movement through the dies and the carriage will then be returned to its original position by return springs 220 and 221 seen in FIGS. 3, 4, 5 and 6. Such springs are mounted in recesses in the bracket 154 and in the die block 169 at the exit end of the carriage.

To limit the return movement of the carriage so that it will be precisely positioned for the neXt severing cycle, rods 223 and 224 are provided threaded in cars 225 and 226 on the die block 169 and such extend through apertures 227 and 228 in ears 229 and 230 on the bracket 154. Sto nuts 231 and 232 are threaded on the ends of the rods 223 and 224, respectively, which will engage the ears 229 and 230 limiting the return of the carriage. When the stock moves the carriage, the rods 223 and 224 will project through the apertures 227 and 228. Since all of the components of the die assembly are allochirally identical in form on either side of the blade B, the bracket 153 will also be provided with ears 234 and 235 which may similarly cooperate with ears 236 and 237 on the die block 168. When the workpiece speeds are such that the carriage requires to move with the tube for a short distance, the rod assemblies will not be provided between the ears 236, 234, and 237, 235. However, at certain tube speeds, it may be desirable to lock the carriage in a fixed position and rods similar to those shown at 223 and 224 may be provided extending between the pairs of ears to fix the carriage with respect to the brackets and thus respect to the blade B.

Pneumatic control system Referring now to FIGS. 10 through 17 and 18, four three-way solenoid operated valves, normally closed, 240, 241, 242 .and 243 are operated by solenoids 244, 245, 246 and 247 shown in FIG. 18. The valves 241 and 243 may be termed high pressure valves and may be connected to a source of air under extremely high pressure by means of conduits 249 and 250. Such high pressure air, which may be on the order of from 500 to 1000 pounds per square inch, may be supplied from a reservoir and pump unit. The valves 240 and 242 may be termed low pressure valves and are connected to a suitable source of air under relatively low pressures through conduits 251 and 252, respectively. Exhaust conduits 254, 255, 256 and 257 are connected to each valve, Such valves are paired, and the valves 240 and 241 are in parallel with each other and in series with the shuttle valve 32. Similarly, the valves 242 and 243 are paired and are in parallel with each other and in series with the shuttle valve 33. The supply conduits leading from the paired valves to the shuttle valves are connected to the tapped ports 41 and 42 at the opposite ends thereof. Such shuttle valves then communicate through the center ports 43 and 44 thereof to the opposite ends of the cylinder 17.

In this manner, air under pressure is supplied to opposite ends of the cylinder 17 causing the piston 27 and thus the rod 21 to reciprocate back and forth at the direction of the latches 83 and 84 so that the blade B will move between the dies through which the tubular workpiece T passes severing the same on each stroke thereof. Air, supplied at extremely high pressura at either end of the cylinder 17, will then force the blade B to the opposite end of its stroke with a substantially explosive force driving the blade through the tube. The cut-Off is then powered solely by gas pressure and does not require a myriad of motors, clutches, and electrical controls therefor. The high pressure for the operation of the cut-off may be obtained from a convenient plant source and through the use of boosters or pressure regulators, the necessary higher air pressures can be obtained.

Referring now to FIG. 18, there is illustrated a schematic wiring diagram for operation of the valves 240 through 243. The control circuit includes two mains 260 and 261 between which the illustrated electrical components are connected. Push button switch 262 may be termed an off switch and may be utilized to deenergize reset relay 263. Such relay may be energized by push button switch 264 which is in parallel with a normally open holding switch 265 which is closed by the relay 263. A safe-run selector switch 266, illustrated in the safe condition, may be moved to the run condition to energize safety and condition interlocks, schematically shown at 267, when the relay 263 is energized by switch 264.

The relay 263 also closes normally open switch 270 in main 260. The closing of switch 270 by relay 263 energizes solenoid 245 of high pressure valve 241 through the closed contacts 271 of limit switch 272 and normally closed switch 273 in parallel with resistor 274. At this time, a timer 275 is also energized and after solenoid 245 is energized, the timer 275 opens switch 273 holding the solenoid 245 energized at reduced voltage to obtain faster drop-out later. The timer 275 also Opens normally closed switch 276 in series with solenoid 246 and closes normally open switch 277, the latter energizing relay 278 if flag limit switch 279 is in the position shown. The relay 278, when actuated, closes switch 280 preparing the circuit to the trigger circuits 281 which operate the latch solenoids 94 and 95 as well as valve controlling the collet closing piston-cylinder assemblies 197 and 198.

The flag limit switch 279 may be mounted an adjustable distance from the cut-off and operates to measure the length of tube extending beyond the cut-off and thus the length to be severed. The tube generally contacts a mechanism known as a flag which may then be effective to actuate the switch 279. If there is no flag under the limit switch 279, it will be in the position shown in FIG. 18. However, when a tube strikes the flag, the switch arm will move momentarily to the contact 282 sending a pulse to the trigger circuits 281 through the now closed switch 280. The latch solenoid 94 is then energized to retract the latch 83 and the blade B now moves out under high pressure supplied by valve 241 to strike and sever the tube. As the blade B moves through the tube, the limit switch 272 is released opening contacts 271 deenergizing timer 275 and valve solenoid 245, the former now again closing switches 273 and 276. The deenergization of timer 275 also acts, on delay, to close switch 284 in series with the solenoid 244 for the valve 240. Thus solenoid 244 is not immediately energized since the timer contact 284 is timing closed. However, the shift of contacts 271 of the limit switch 272 immediately energizes solenoid 246 of the valve 242 as well as timer 286 which then opens switch 287 in parallel with resistor 288. The energization of the solenoid 246 applies low pressure air to the right hand end of the cylinder 17 as the pistons move to the right as seen in FIG. 12, for example. Such low pressure air acts as a brake to slow the blade down and the frame 66 will then decelerate and yet move so that the pin 82 will engage latch 84 on the right hand side of the machine as seen in FIG. 1, for example. As soon as the frame is latched at the end of its stroke, limit switch 290 is actuated opening contacts 291 deenergizing solenoid 246 and timer 286. At this time, the valves are then in the condition shown in FIG. 13.

The flag limit switch 279 will be cleared of the cut piece as soon as the cut is made usually by a lateral ejector and will return to the position shown in FIG. 18. When the limit switch 290 is energized opening contacts 291 to deenergize solenoid 246, contacts 293 are closed energizing solenoid 247 for valve 243 as well as timer 294 which opens normally closed switch 295 in parallel with resistor 296 so that the solenoid 247 will be held at reduced voltage obtaining a faster later drop-out. The timer 294 also closes normally open switch 297 again to energize relay 278 closing switch 280 to prepare the circuit to the triggering circuits 281 so that when the flag limit switch 279 is again actuated by the next length of tube, such triggering circuits will be energized. Timer 294 also opens normally closed switch 298 in series with the solenoid 244 of the valve 240.

The energization of solenoid 247 opens valve 243 to supply high pressure to the right hand end of the piston 27 as viewed in FIG. 14, for example, but the piston and blade will not move because of the engagement between the pin 82 and latch 84. Only when the flag limit switch 279 is actuated, will the solenoid 95 be energized to release the latch and let the blade traverse back to the left as seen in FIG. 1 through thhe tube. Again, as the blade moves through the tube, limit switch contacts 293 move back to the position shown in FIG. 18 energizing the solenoid 244 of valve 240 as well as timer 360 which opens switch'301 in parallel with resistor 302. Thus the valve 240 is opened as viewed in FIG. 16 so that the piston 27 moves to the left or the end of its stroke under its momentum against the low pressure applied through such valve to the left hand end of the cylinder 17. The switch 290 also deenergizes solenoid 247 and timer 294, the latter then reclosing switch 295 and opening switch 297. Such timer also serves to close on delay switch 303 so that the solenoid 246 and valve 242 will not be immediately energized until the limit switch 290 is again actuated by the latching of the blade frame in its original position. The limit switch 272 has now returned to its original position closing contacts 271 and opening contacts 384 so that the valve solenoid 245 will again be energized when the frame 66 is latched at the left hand side of the stroke as seen in FIG. 1. Thus the machine has gone through a complete cycle which includes a stroke in one direction and a stroke in the opposite direction, making two severing cuts in the process.

Operation Briefly recapitulating the operation of the illustrated cut-off, and with special reference to FIGS. 10 through 17, with the frame 66 at the left hand end of its stroke as viewed in FIG. 1 and firmly latched by the latch 83 in such cocked position, the valve 241 will be opened supplying high pressure air through the shuttle valve 32 to the left hand side of the piston 27. The valves 240, 242 and 243, will at this time be closed. When the trigger circuits 281 are energized by the flag limit switch 279, the piston 27 and thus the blade B will move to the right as indicated by the arrow 305 in FIG. 10. Due to the extremely high air pressure developed, the blade will move initially at an extremely high acceleration rate and with almost an explosive force. Air on the right hand side of the piston 27 within the cylinder 17 may be exhausted through the center exhaust ports 48 and 49 and through the exhaust conduit 257 of the valve 243. The piston now moves to the right as seen in FIG. 11 at an extremely high velocity and will reach its maximum velocity at approximately the center of its stroke as seen in FIG. 12. The piston-cylinder assemblies 197 and 198, actuating the two gripping collets, will be energized by the trigger circuits 281 and the blade will then move through the work between the pairs of collets and depending upon the tube speed, the two gripping dies as well as the blade may move a short distance with the tube. When the piston 27 reaches the center of its stroke, as seen in FIG. 12, several conditions change. The valve 241, heretofore open supplying high pressure behind the left hand side of the piston 27, is now closed and the valve 242 is now opened supplying low pressure air through the shuttle valve 33 to the right hand end of the cylinder 17. The shuttle valve member 37 shifts accordingly. Also, the exhaust ports 48 and 49 are now blocked. As the blade moves through and beyond the workpiece, exhaust ports 48 and 49 will again be opened permitting the high pressure air on the left hand side of the piston now to exhaust therethrough. The low pressure air now trapped in the right hand end of the cylinder acts as a dashpot or brake slowing the blade to a halt at the end of its stroke. At the end of the blade stroke, as seen in FIG. 13, the latch 84 will engage the pin 82 holding the frame 66 at the right hand end of its stroke. All of the valves 240 through 243 are now closed.

For the repeat cycle, as seen in FIGS. 14 through 17, the high pressure valve 243 is first opened shifting the shuttle 37 of valve 33 supplying high pressure now to the right hand end of the piston 27. The frame .66 will be held in this position until the flag limit switch 279 again triggers the circuits 281 releasing the latch 84 through solenoid 95. With higher pressure continuing to be supplied through the open valve 243, the piston 27 and thus the blade B is now explosively moved to the left as seen by the arrow 306 in FIG. 15. Air on the left hand side of the piston 27 is exhausted through the ports 48 and 49 so that there is no retarding or dashpot effect on the piston until such ports are closed. The blade now again enters the tube making the severing operation as seen in FIG. 16 and the piston 27 closes the exhaust ports 48 and 49. At this time, the high pressure valve 243 is closed and the low pressure valve 240 is opened shifting shuttle 36 and supply low pressure air to the left hand side of the piston 27 as seen in FIG. 16. Such low pressure air acts as a retardant for the blade braking the same to a stop at the end of its stroke wherein it will be latched into position as the latch 83 engages the pin 81. The high pressure air behind the piston 27 or on the right thereof as seen in FIG. 17 is then exhausted through the ports 48 and 49. The next condition obtained will be the same as that shown in FIG. 10 wherein the blade B is ready to be shot back again through the tube as the flag limit switch again energizes the triggering circuits. Instead of a physical contact between the tube end and a flag, more esoteric tube length measuring devices may be employed to trigger the switch 279. Also, it will be appreciated that especially when workpieces of a nature that may buckle when the collets clamp the same are being severed, special accelerator mechanisms may be employed to shift the blade a relatively short distance so that it will move with the workpiece as Well as the carriage 152 supporting the tube clamping dies. Such mechanism may, of course, be actuated by the triggering circuits 281.

It can be seen that the velocities obtained by the substantially explosively actuated blade are such that a relatively short distance of tube-blade travel is required for a flying shear. For example, the blade may be travelling at approximately 100 feet per second as it strikes the tube and with a tube moving at 500 feet per minute, the blade will not be deflected in the direction of the tube movement any great extent. For example, for a one inch tube, /8 of an inch may be the maximum play required in the blade for a tube moving at 1,000 feet per minute. The distance the blade moves can, of course, readily be controlled by varying the depth of the recess 115 in the bridge plate 101 connecting the legs 67 and 68 of the U-shape members of the frame 66.

Blade speeds significantly greater than conventional press blade speeds, which are on the order of 5 feet per second are obtained. Speeds of the blade of the present invention ranging, for example, from about 40 to about 200 feet per second at impact will ordinarily be used. Such substantially higher blade speeds are developed by the high pressure blade driving force.

It can now be seen that there is provided a highly simplified cut-off for tubes and the like which would itself not be a limiting factor in the speed of operation of the production line.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. The method of making successive cuts in an elongated travelling tubular workpiece and the like comprising the steps of applying a high pressure driving force to a cutting tool while holding such cutting tool stationary to build up a substantially explosive driving force, and releasing such cutting tool to drive the same substantially explosively fully through such workpiece at high speed in one direction to sever such workpiece; and then substantially explosively driving such tool without reversal thereof fully through such workpiece in the opposite direction at high speed again to sever such workpiece.

2. The method of severing elongated tubular products and the like comprising the steps of mechanically latching a cut-off blade in a cocked position, applying a high pressure driving force to such blade while latched, and releasing such blade on a predetermined tube length signal, whereby the blade is driven substantially explosively freely and completely through such product by such high pressure driving force.

3. The method of severing elongated travelling tubular products and the like comprising the steps of mechanically latching a cut-off blade in a cocked position, applying a high pressure driving force to such blade, releasing such blade on a predetermined signal, whereby such high pressure driving force will substantially explosively drive such blade fully through such tubular product severing the same, and applying a low pressure braking force to such blade to stop the same on the opposite side of such product. p

4. The method of claim 3 including the step of mechanically latching .such blade on the opposite side of such product in a cocked position, and applying a high pressure driving force to such blade for return of the blade to its original position on release thereof.

5. The method of severing elongated mill products and the like comprising the steps of latching a symmetrical cut-off blade in a cocked position, triggering such blade and substantially explosively driving such blade fully through such product to sever the same, braking such blade to a stop, and latching such blade in a cocked position on the opposite side of the product.

6. The method of severing an elongated travelling tube comprising the steps of holding a cut-off blade in a cocked position, applying a high pressure on such blade tending to drive the same through such travelling tube, releasing such blade thus substantially explosively to drive such blade fully through such tube, applying a lower progressively increasing braking force to such blade to stop the same on the opposite side of the travelling tube, holding such blade on the opposite side of such tube, applying a high pressure force to such blade tending to drive the same back through such travelling tube, releasing such blade substantially explosively to drive such blade again fully through such travelling tube in the return direction, applying a lower progressively increasing braking force to such blade to stop such return of the same, and holding such blade again on the original side of such tube for application again of such high pressure driving force.

7. The method of severing elongated travelling tubes comprising the steps of holding a symmetrical cut-off blade in a cocked position, applying a high pressure driving force to such blade, releasing such blade on a predetermined tube length signal, whereby such driving force will rapidly accelerate such blade substantially explosively driving the same fully through such travelling tube, braking such blade to a stop, and mechanically latching the same on the opposite side of the tube.

8. A tube cut-off comprising a base, three aligned stanchions secured to said base, a cylinder extending between the middle and an end one of said stanchions, spaced guide means extending between said middle and the 0pposite end one of said stanchions, frame means mounted on said guide means for reciprocation therealong, a piston in said cylinder, a rod extending through said cylinder and connected to said frame means for moving the same along said guide means, and a tube cut-off blade mounted on said frame means, tube guide means for passing a tube through the frame means to one side of said blade, the blade being operative to sever a tube in either direction of movement thereof.

9. A tube cut-off as set forth in claim 8 including high and low pressure air valves selectively connectible to each end of said cylinder.

10. A tube cut-off as set forth in claim 9 including shuttle valves mounted on the stanchions supporting said cylinder and connected thereto, and a high and low pressure valve connected to the opposite end of each shuttle valve.

11. A tube cut-off as set forth in claim 3 including latch means on the stanchions supporting said guide means operative to hold said frame at either end of its stroke.

12. The method of severing elongated tubular products and the like comprising the steps of mechanically latching a cut-off blade in a cocked position, applying a high pressure driving force to such blade, releasing such blade on a predetermined tube length signal, with the blade thereby driven substantially explosively freely and completely through such product, applying a braking force to such blade as it moves through such tubular product to slow the blade to a stop, and mechanically latching such blade on the other side of such tubular product for application of a high pressure driving force again to drive such blade completely through such tubular product in the opposite direction when released.

13. A tube cut-off comprising a rectangular frame, a symmetrical cut-off blade having oppositely directed cutting edges centrally mounted in said frame, guide means extending transversely of the axis of such tube, means mounting said frame on said guide means for movement therealong, and drive means connected to said frame operative to reciprocate said frame to drive said blade completely through such tube in either direction of movement thereof, said drive means comprising an air operated piston-cylinder assembly, the rod of which extends completely through the cylinder thereof and is connected to said frame.

14. A tube cut-off as set forth in claim 13 including means to supply selectively high and low pressure air to opposite ends of said piston-cylinder assembly.

15. A tube cut-01f comprising a rectangular frame, a symmetrical cut-off blade having oppositely directed cutting edges centrally mounted in said frame, guide means extending transversely of the axis of such tube, means mounting said frame on said guide means for movement therealong, and drive means connected to said frame operative to reciprocate said frame to drive said blade completely through such tube in either direction of movement thereof, said drive means comprising a double acting piston-cylinder assembly, the rod of which is connected to said frame.

16. A tube cut-off comprising a rectangular frame, a symmetrical cut-off blade having oppositely directed cutting edges centrally mounted in said frame, guide means extending transversely of the axis of such tube, means mounting said frame on said guide means for movement therealong, drive means connected to said frame operative to reciprocate said frame to drive said blade completely through such tube in either direction of movement thereof, and means releasably to latch said frame against movement at each end of its reciprocatory stroke.

17. A tube cut-off comprising a rectangular frame, a symmetrical cut-off blade having oppositely directed cutting edges centrally mounted in said frame, guide means extending transversely of the axis of such tube, means mounting said frame on said guide means for movement therealong, drive means connected to said frame operative to reciprocate said frame to drive said blade completely through such tube in either direction of movement thereof, dies on each side of said guide means between which said blade passes to sever such tube, and means interconnecting said dies, each die including a tube gripping collect, and means mounting said dies for short distance movement axially of such tube.

18. A tube cut-off as set forth in claim 17 including means mounting said blade on said frame for short distance movement axially of such tube.

19. A tube cut-off as set forth in claim 18 including carriage means at opposite ends of said blade, and means mounting said carriage means on said frame for such movement.

20. A tube cut-off as set forth in claim 19 including spring return means for said dies and said carriage means.

21. A tube cut-off as set forth in claim 17 wherein each collect includes a pair of tube gripping members split in a plane normal to the direction of movement of said blade.

22. A tube cut-0E as set forth in claim 21 including a collect actuating fork for each pair of tube gripping members, means firmly supporting one end of said members, and wedge surfaces on said fork engaging said members to force the same together.

23. A tube cut-off as set forth in claim 16 wherein said symmetrical cut-ofi blade comprises oppositely directed tube severing edges each including center projecting portions having reverse curve edges on the opposite sides thereof.

24. A tube cut-0E as set forth in claim 16 including dies on each side of said guide means between which said blade passes to sever such tube.

References Cited by the Examiner UNITED STATES PATENTS 1,714,785 5/1929 Hudson 83355 1,955,004 4/1934 Lodge 83355 X 2,620,993 12/1952 Jeffrey 83-614 X 3,040,611 6/1962 Tournaire 83-694 3,213,735 10/1965 Keferstein et a1. 83639 X ANDREW R. JUHASZ, Primary Examiner. 

1. THE METHOD OF MAKING SUCCESSIVE CUTS IN AN ELONGATED TRAVELLING TUBULAR WORKPIECE AND THE LIKE COMPRISING THE STEPS OF APPLYING A HIGH PRESSURE DRIVING FORCE TO A CUTTING TOOL WHILE HOLDING SUCH CUTTING TOOL STATIONARY TO BUILD UP A SUBSTANTIALLY EXPLOSIVE DRIVING FORCE, AND RELEASING SUCH CUTTING TOOL TO DRIVE THE SAME SUBSTANTIALLY EXPLOSIVELY FULLY THROUGH SUCH WORKPIECE AT HIGH SPEED IN ONE DIRECTION TO SEVER SUCH WORKPIECE; AND THEN SUBSTANTIALLY EXPLOSIVELY DRIVING SUCH TOOL WITHOUT REVERSAL THEREOF FULLY THROUGH SUCH WORKPIECE IN THE OPPOSITE DIRECTION AT HIGH SPEDD AGAIN TO SEVER SUCH WORKPIECE. 